For purposes of background, a “zither” is a specialized type of chorded or stringed musical instrument. More specifically, zithers include any one of several stringed musical instruments that consist of a flat, shallow resonator box (sets horizontally before the performer when in use) overlaid with a multiplicity (e.g., 20 to 40) of strings (also commonly referred to as “chords”). The strings nearest the performer when in use run above a fretted fingerboard against which they are stopped by the left hand to provide melody notes. The strings are generally plucked by a plectrum worn on the right thumb. At the same time, the right hand fingers pluck an accompaniment on the farther strings, which remain unstopped. The zither is capable of playing notes arranged in a series of octaves.
An “autoharp” is generally considered to be a specialized type of zither on which a simple harmony may be obtained by button-controlled dampers (operating in sets) that when depressed leave free the strings of the desired chord. U.S. Pat. No. 257,808 to Zimmermann discloses the original autoharp. More specifically, U.S. Pat. No. 257,808 teaches a musical instrument having a multiplicity of strings arranged in a number of octaves over a resonating box, wherein a series of chord bars are provided together with a series of dampening pads which engage selected strings when the chord bar is depressed. Thus, only certain of the strings are free to vibrate or give sound when strummed or picked. Further, the dampening is generally selected such that when a particular chord bar is depressed only those selected strings which constitute the notes in that chord are free to vibrate.
Manufactured and luthier-built autoharps generally have up to 21 spring-loaded or flexible levered chord bars rigidly fastened to the body of the autoharp, producing from one to five keys. Because the chord bars remain in a fixed position relative to the underlying strings, it difficult to play songs in keys the autoharp does not have. Accordingly, there is a need in the art for new and improved stringed musical instruments (including zithers and autoharps) that enable the playing of every key in the normal chromatic scale of 12 keys. In addition, there is a need in the art for stringed musical instrument retrofit kits that enable luthiers to modify existing stringed musical instruments (including zithers and autoharps) such that existing chord bars may be adjustably positionable relative to the underlying strings. The present invention fulfills these needs and provides for further related advantages.